Patterson and Cottral (1950) reported that arteriosclerosis of chickens was a part of the neurolymphomatosis disease process and therefore their studies had no direct application to human arteriosclerosis. However, abundant data has clearly established that neurolymphomatosis (Marek's disease) is caused by a specific cell associated herpesvirus. A linkage of the Marek's virus to arteriosclerosis of chickens may be of great significance in understanding the human disease. This is because it has been well established that similar herpesviruses are widely distributed as latent infections in the human population. The need for these studies is supported by the de novo synthesis of lipids and cholesterol crystals in cell cultures infected with a similar herpesvirus described by us. Further, the wide variety of cytopathological capabilities of the herpesviruses described by many investigators also support the validity of this study. We have available technical knowledge and tools which were unknown at the time that Patterson and Cottral made their studies. These are: a well defined virus and specific pathogen free flocks of chicken of known genetic susceptibility to Marek's disease. These chickens are free of all known avian pathogens. One flock is relatively resistant while the other flock is susceptible to Marek's disease. Our proposed experimental studies could specifically assess the role of the Marek's herpesvirus in the pathogenesis of arteriosclerosis of chickens.